Most modern computer systems include the capability to limit power consumption by suspending or hibernating the system as a whole when the system is not in use. Some operating systems also include the capability to reduce the power levels for some system components. For instance, the power that is provided to the central processing unit (CPU) of a computer system may be reduced. As another example, the display screen may be dimmed to conserve power consumption by the computer system.
Power consumption may be similarly controlled with respect to different types of Input/Output (I/O) functionality including but certainly not limited to Ethernet, ATM, Fibre Channel, Infiniband, SCSI, etc. Data is typically transmitted and received across an I/O interconnect via an interface (i.e., I/O interface) that can either be an embedded device or a host bus adapter. For instance, the interface may be a Network Interface Card (NIC), a SCSI card, Fibre Channel, ATM, Myranet, InfiniBand, USB, Firewire (1394), etc. While some systems include a single interface for a particular I/O technology, computer systems in a server environment often include multiple interfaces. In order to reduce the power consumption associated with the interfaces, each individual interface may be powered on, powered down or powered to an intermediate state (e.g. card powered on but PHY powered off). In other words, the power consumption of each interface is individually managed.
In view of the above, it would be beneficial if power consumption associated with a pool of resources such as interfaces of a given I/O technology could be accomplished in a more effective manner.